In most "gaited" breeds, an ambling gait is a hereditary trait.[5][6] This mutation may be a dominant gene, in that even one copy of the mutated allele will produce gaitedness.[5] However, some representatives of these breeds may not always gait. Conversely, some naturally trotting breeds not listed above may have ambling or "gaited" ability, particularly with specialized training. Many horses can both trot and amble, and some horses pace in addition to the amble, instead of trotting. However, pacing in gaited horses is often, though not always, discouraged,[1] though the gene that produces gaitedness appears to also produce pacing ability.[5] Some horses do not naturally trot or pace easily, they prefer their ambling gait for their standard intermediate speed.[1] A mutation on the gene DMRT3, which controls the spinal neurological circuits related to limb movement and motion, causes a "premature 'stop codon'" in horses with lateral ambling gaits.[6][5]